- since 60% expected to use foil, 40% are not expected to use foil and probability not use foil is 0.40
expected number to not use foil is sample size (22) * probability not use foil (0.40) = 8.8 ~ 9
2. probability 5 do not use foil can be found using binomial formula
22!
---- (0.4)^5 * (0.6)^17 = 0.0456
5! 17!
3. all 22 not use foil, means find probability 0 not use foil, using binomial formula
22!
---- (0.4)^0 * (0.6)^22 = 0.0456 ~ 0 (so would be very surprised)
0! 22!
Mikayla J.
thank you for your help! I appreciate it so much10/21/20